1. Field of the Invention
This invention relates generally to applicators and more specifically to a device for applying liquid adhesive to a work-piece.
2. In the furniture industry, for example, work-pieces in the form of lengths of wood are joined together by an adhesive, often a liquid glue. In the past, to facilitate applying liquid glue to pieces to be joined, the pieces or portions of the pieces immersed into the liquid adhesive before securing them together. Thus, the work-pieces to be glued were placed on a device which moved them into and out of an adhesive bath to dip a succession of work-pieces into the adhesive. However, such dipping devices have a disadvantage in that the work piece is often covered with an excess of adhesive which is difficult to remove and which excess adhesive also causes unnecessary sticking of the item during the subsequent manufacturing operations.
An example of an earlier device capable of applying liquid adhesive in U.S. Pat. No. 1,943,647 to Weller which discloses a pad, that presumably can support a work-piece, lowered into a fluid by depressing a platform supported by springs.
Another known device is U.S. Pat. No. 1,959,341 to Bowlen, which discloses the transfer of glue from a reservoir to a fixed glue applicator plate by means of an oscillating applicator plate and then placing the work-piece in contact with the fixed applicator plate.
U.S. Pat. No. 2,293,747 to Koch discloses an apparatus for coating the edges of wood strips which are positioned by rollers in a glue tub. The level in the glue tub is held constant by dipping the glue tub into a lower tub by means of a treadle.
Also of interest is U.S. Pat. No. 213,453 to Ruger which discloses a device for applying powdered sugar on confections using a flexible bottom that, when rebounded from pressure by a plate, throws powdered sugar onto the surface of items fastened to the underside of the plate.
All of the devices discussed suffer from the disadvantages which the present invention seeks to overcome.